The Wave Energy Converter (WEC) has been known for many years; it was only during the last decade and a half or so that serious efforts were initiated towards exploiting it commercially. Several ocean wave energy conversion devices have since been developed, but only a few matured to full-scale trial stage, but none yet implemented fully on a commercial scale. The main disadvantage of the wave power is the uneconomical cost of extracting wave energy.
Reference is made to patents/applications and/or devices which have some similar components termed flexible pipes and inlets, such as shown in patent documents SU 1129407 A, RU 2004 837 C1, U.S. Pat. Nos. 4,163,633, 5,808,368, 3,333,667, GB-A-2 024 957, WO 84/00583 A and WO 2006/067421.
In the cases cited above the flexible pipe essentially contains devices like the “check valves”, or non-return valves, or valves, membranes, baffles, diaphragms, bellows, or combination of these; which are purported to be means for preventing reverse flow and/or to developing pressure. On the contrary, such components not only create extra friction, but under actual wave conditions could even lead to stoppage of the flow altogether. Whereas, the present invention has no components inside the flexible pipe.
Further, since the check valves preclude reverse flow, these devices cannot be classified as “non-positive displacement pumps”, wherein reverse flow is a class characteristic, but “positive displacement pumps”, instead. Whereas, since reverse is possible in the present invention, it would be classified as a non-positive displacement pump; distinct by classification as well.
The inlets of each of the other systems are also quite different from that of the present invention, in terms of their respective principle of operation, means, methods, construction, arrangement of the components, etc. The Soviet invention (SU 1129407 A) mentions controlling the buoyancy of the tanks, but without reciting either the means or methods of achieving it. Some systems have plurality of inlets and outlets on each flexible pipe. Yet again, all being quite different from the present invention in ways more than one.
The inlet of the present invention is unique. It performs several essential functions, such as ingesting separate and proportioned separate “Slugs” of air and water, without which such a system cannot operate, i.e. if the transverse wave function is to be exploited to convert wave energy, then “Slugs” of air and water must be formed in the “flexible pipe” to create flow and pressure, without which neither can occur.
For instance, in the patent RU 2004 837C1 the flexible pipes are completely and always filled with water. Since the Still Water Level is not inclined, and the waves oscillate on this datum, there can be no gradient created along the pipe. Hence, the water in the said device cannot, and does not flow. The non-return valves/check valves in the pipe would be of no consequence. Whereas, the present invention essentially has “Slugs” of both, air and water.
Further, in the above case “floats” are also attached to the flexible pipe for buoyancy. Whereas, in the present invention, buoyancy to the “flexible pipe” is provided by the air “Slugs”.
Furthermore, the flexible pipes in certain cases are bellows, stretchable like a coil spring. Whereas, the present invention has neither.
It could also be appreciated that, all the above methods employ a totally different principle of operation as compared to the present invention, have moving/contacting components, are different in construction, means and methods, and thus prone to suffering the disadvantages similar to those of the other state of the art WECs.
The object of the present invention, therefore, is to overcome the challenges of wave energy, by making it cost competitive with the conventional power.
It is important to note that, in case of the present invention, in the inside of the “Flexible Pipe” there are no contacting components, appendages, non-return valves or check-valves, cavities, openings, holes, diaphragms and the like which exists in the conventional energy converters. Contrary to belief the said non-return valves in the flexible pipe do not prevent the occurrence of surge or stall, hence they have not been provided in the present invention. Non-return valves hinder exchange of fluids between adjacent slugs of air/water, which might normally happen due to variation in the wave parameters.